GB1594354A

GB1594354A - Device for turning the rotor of a gas turbine engine

Info

Publication number: GB1594354A
Application number: GB23407/77A
Authority: GB
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 1977-06-02
Filing date: 1977-06-02
Publication date: 1981-07-30
Also published as: US4193739A; DE2822998A1; FR2403454A1; DE2822998C2; JPS5439714A

Description

PATENT SPECIFICATION ( 11)

1594354 Application No 23407/77 ( 22) Filed 2 June 1977 Complete Specification filed 19 May 1978

Complete Specification published 30 July 1981

INT CL 3 F 02 N 9/04 ( 52) Index at acceptance -1 F 1 K 4 C 2 A 4 E 6 81 ( 72) Inventor DESMOND CHARLES LUCEY ( 54) DEVICE FOR TURNING THE ROTOR OF A GAS TURBINE ENGINE ( 71) We, ROL Ls-Ro YCE LIMITED, a the rod, compressed air admitt British Company, of 65 Buckingham Gate, chamber on opening of the va London SW 1 E 6 AT, do hereby declare the the piston a first force urg invention, for which we pray that a patent toward the second chamber; may be granted to us, and the method by applying a second force in opl which it is to be performed, to be particularly first force thereby to urge the described in and by the following state the first chamber when said fi ment: on closing of said valve.

This invention relates to a device for Also according to this inver turning the rotor of a gas turbine engine e g described is provided in comi for the purpose of inspecting the turbine gas turbine engine having a x blades of the engine an annular surface, radial E In this connection it is the practice to insert adjacent said surface and a cx an optical viewing device through an aper said rotor, wherein said cylind ture in a casing of the engine to be able to is secured to said casing and view the said blades, and to turn the rotor an aperture through which sa slowly so that the blades are seen in succes into a position in which sion at the viewing device For efficient situated adjacent said blades working it is necessary for the operator to emerging from said nozzle have control over the turning and stopping of blades to turn the rotor, am the rotor so that when a faulty blade is seen pad of friction material, is sit the operator can easily stop and if necessary said annular surface to brak reverse the rotor It is an object of this occurrance of said second for invention to provide a turning device provid In operation, the second 1 ing such control acts to apply a braking forc According to this invention there is pro When the valve is operated t vided a device for turning the rotor of a gas pressure into said first chaml turbine engine, comprising a member inser rotor, said air pressure acts o table through an aperture in the casing of the exert said first force to free engine into a position adjacent blades pro rotation When the valve is ol vided on the rotor, said member including off said air pressure the second means for directing a pressurised gas on to ately acts to stop the rotor said blades so as to cause rotation of said satisfactory control over stop rotor, and means for urging said member ing the rotor is attained.

into friction engagement with the rotor for An embodiment of this inv stopping thereof be described with reference t( Preferably the device comprises: a cylinder nying drawings wherein:connectable to a source of compressed air; a Fig I is a diagrammatic il piston contained within the cylinder and gas turbine engine and a dev dividing the cylinder into first and second the rotor of the engine.

chambers, the cylinder having an end wall at Fig 2 is an enlarged and se said first chamber; a tubular rod secured to the device.

the piston and extending axially slidably Fig 3 is a section on the 1 through said end wall; a valve openable to Fig 2.

admit air from said source to said first The engine (Fig 1) compril chamber; and inlet port in said rod for or rotors 10, 11, 12 enclosed admitting air from said first chamber to the Each rotor comprises a coml interior of the rod; a lateral nozzle provided aggregate 10 A, 1 OB; 1 1 A, 1 1 B in said rod exteriorly of the cylinder; a pad of While, for purpose of being t friction material provided at the free end of and third rotors 10, 12 are usi ed into the first lve exerting on ing the piston and means for position to said 55 e piston toward rst force ceases ition the device :bination with a 60 rotor including aerofoil blades asing enclosing er of the device said casing has 65 Lid rod extends said nozzle is and a jet of air -an act on the d wherein said 70 uated adjacent e the rotor on ce.

force normally :e to the rotor 75 o introduce air ber to turn the n the piston to the rotor for perated to shut 80 d force immediIn this way ping and startmntion will now 85 o the accompallustration of a ice for turning ctional view of line III-III in ses three spools 95 by a casing 13.

pressor-turbine and 12 A, 12 B. urned, the first ially accessible 100 Ir" ( 21) ( 23) ( 44) ( 51) ( 19) 1,594,354 from outside the casing the intermediate rotor 11 is not easily accessible The invention is particularly useful for, though of course not limited to, turning the rotor 11.

Fig I shows an optical viewing device or boroscope 14 in position for inspection of blades of the turbine 11 B For the purpose of such inspection, the turbine I l B is turned by the device, denoted 15, acting on the compressor l IA.

The device 15 (Fig 2) comprises a cylinder 16 having end walls 20 21 A piston 17 in the cylinder 16 divides the cylinder into a first chamber 18 and a second chamber 18 A A tubular rod 19 secured to the piston 17 extends axially slidably through the end wall to the exterior of the cylinder 16 The cylinder is releasably secured to the outside of the casing 13 and the rod 19 extends through an aperture 13 A in the casing substantially radially in respect of an annular surface 22 of the rotor I IA The chamber 18 A, which is open to atmosphere, contains a spring 23 acting on the piston 17 to press a friction pad 24 provided at the free end of the rod 19 against the surface 22 thereby to provide on the rotor a braking force 27 opposing rotation of the rotor The pad is made of a suitable friction material e g.

rubber.

When it is desired to turn the rotor, a manually operated valve 25 is operated to admit compressed air from a pump 26 to the first chamber 18 of the cylinder The resulting rise in pressure in the chamber 18 creates on the piston 17 a release force 28 opposing the braking force 27 applied by the spring so that the pad 24 is lifted from the surface 22 and the rotor becomes free to be turned.

Simultaneously, the air passes through an inlet port 29 provided in the rod inside the chamber 18 and issues from a lateral outlet port or nozzle 30 provided in the rod outside the cylinder The air issues from the nozzle 30 in the form of a jet acting on adjacent aerofoil blades 31 of the rotor to turn the latter A non-circular extension 32 of the piston prevents rotation thereof so that the nozzle 30 is kept at the angle at which the jet acts on the blades 31 to turn the rotor in the one direction 33 of rotation, (Fig 3).

For the purpose of turning the rotor in the opposite direction 34 of rotation the device includes a second cylinder 35 containing a second piston 36 secured to the rod 19 A sleeve 37 surrounding the rod 19 with clearance therebetween has an inlet port 38 inside the second cylinder 35 and an outlet port or nozzle 39 situated adjacent the nozzle 30 of the rod 19 but at an angle whereby a jet 40 issuing from the nozzle 39 turns the rotor I IA in the direction 34 The valve 25 has a valve member 25 A settable for directing the air supply selectively to either the cylinder 16 or to the cylinder 35 The friction pad 24 is released by air pressure on the piston 36 in the same way as was described in respect of the piston 17.

It will be seen that the valve 25 can be operated to turn the rotor in either direction of rotation, and that when the valve is set to shut-off the supply to either cylinder 16, 35 the rotor is stopped by action of the pad 24.

Claims

WHAT WE CLAIM IS: 75

1 A device for turning a rotor of a gas turbine engine, comprising a member insertable through an aperture in the casing of the engine into a position adjacent blades provided on the rotor, said member including 80 means for directing a pressurised gas on to said blades so as to cause rotation of said rotor, and means for urging said member into friction engagement with the rotor for stopping thereof 85

2 A device according to claim 1 comprising: a cylinder connectable to a source of compressed air; a piston contained within the cylinder and dividing the cylinder into first and second chambers, the cylinder having an 90 end wall at said first chamber; a tubular rod secured to the piston and extending axially slidably through said end wall; a valve openable to admit air from said source to said first chamber; an inlet port in said rod 95 for admitting air from said first chamber to the interior of the rod; a lateral nozzle provided in said rod exteriorly of the cylinder; a pad of friction material provided at the free end of the rod, compressed air admitted 100 into the first chamber on opening of the valve exerting on the piston a first force urging the piston toward the second chamber; and means for applying a second force in opposition to said first force thereby to urge the 105 piston toward the first chamber when said first force ceases on closing of said valve.

3 A device according to claim 2 in combination with a gas turbine, the engine having a rotor including an annular surface, 110 radial aerofoil blades adjacent said surface and a casing enclosing said rotor, wherein said cylinder of the device is secured to said casing and said casing has an aperture through which said rod extends into a 115 position in which said nozzle is situated adjacent said blades and ajet of air emerging from said nozzle can act on the blades to turn to rotor, and wherein said pad of friction material is situated adjacent said annular 120 surface to brake the rotor on occurrence of said second force.

4 A device for turning the rotor of a gas turbine engine substantially as hereinbefore described with reference to the accompany 125 ing drawings.

For the Applicants, J WAITE, Chartered Patent Agent.

3 1,594,354 3 Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd -1981 Published at The Patent Office, Southampton Buildings, London, WC 2 A Il AY, from which copies may be obtained.

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